Apparatus and Method for Generating Electricity With Pressurized Water and Air Flow Media

ABSTRACT

A facility for generating electricity, including a water source and a plurality of penstocks adapted for selective flow communication with the water source for delivering water from the water source to a turbine electricity generator. An electricity distribution system is provided having a first component adapted to deliver electricity generated by the turbine electricity generator to an electric grid and an alternative second component adapted to use the electricity to power an air compressor. A compressed air storage reservoir is provided for storing air compressed by the air compressor, including an outlet for selectively delivering the compressed air to the plurality of penstocks according to a predetermined sequence for providing energy to the water contained in the penstock to propel the water from the penstock to the turbine.

PRIORITY CLAIM

This application claims priority from and incorporates by reference U.S.Provisional Patent Application Ser. No. 62/729,834, filed Sep. 11, 2018.

TECHNICAL FIELD AND BACKGROUND OF THE INVENTION

This invention relates to an apparatus and method for generation ofelectricity using pressurized water and air as respective flow media,working together to achieve more uniform and efficient electricitygeneration. Pump storage generation of electricity is well-known and isa type of hydroelectric energy storage used by electric power systemsfor load balancing. The method stores energy in the form ofgravitational potential energy of water, pumped from a lower elevationreservoir to a higher elevation reservoir. Low-cost surplus off-peakelectric power is typically used to operate the pumps. During periods ofhigh electrical demand, the stored water in the higher elevationreservoir is released and allowed to fall through turbines to produceelectric power. Although the inherent losses of the pumping process makesuch a facility an overall net consumer of energy, the system increasesrevenue by allowing the utility to sell more electricity during periodsof peak demand when electricity prices are highest.

Pumped-storage hydroelectricity allows energy from intermittent sources,such as solar, wind, and other renewable sources, or excess electricityfrom continuous base-load sources such as coal or nuclear, to be savedfor periods of higher demand. Because of the need to replenish thesupply of stored water, pump hydro facilities are most often used withreservoirs upstream of a hydroelectric facility, with water beingcirculated as needed to balance load demand with supply.

The present invention is not a “pump storage” apparatus and method.Rather, the disclosed invention supplements a supply of water at a highelevation with compressed air generated according to one of severalalternatives. As described in this application the supply of water isfrom, for example, a flowing river, conduit, canal or the like. Ratherthan using off-peak water flow to pump water back up to a higherelevation for later use, the water flow may be continuous from anupstream source, through a turbine and downstream. It is the use towhich the water is put at any given time that results in the efficiencyof the system described in this application. Electricity generatedduring peak demand periods is delivered to the grid for use byconsumers, and electricity generated during off-peak demand periods isdelivered to an air compressor, which compresses and stores thecompressed air for use as a supplemental energy source which, incombination with the flowing water, provides increased and more uniformflow that can balance water flow rates and mimic the power of waterfalling from a high elevation in a system where the upstream intake isnot significantly higher than the discharge end of the system. Onefeature of the invention is the use of residue from the generation ofelectricity by coal, such as CCR (“coal combustion residue”) to servethe beneficial purpose of providing an encasement of the operatingcomponents of the system with enhanced efficiency. The system describedin the application avoids the need to pump water up an incline into astorage reservoir and instead uses the electricity to compress airduring off-peak usage periods.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide anapparatus and method for generation of electricity using pressurizedwater and air as respective flow media, working together to achieve moreefficient electricity generation.

It is another object of the invention to provide an apparatus and methodfor generation of electricity using pressurized water and air thatenables electricity to be generated without the need for a physical dropof the flow media to create the force necessary to operate a turbinegenerator.

It is another object of the invention to provide an apparatus and methodfor generation of electricity using pressurized water and air that usesCCR as a construction material to enclose some or all of the operatingcomponents of the system.

It is another object of the invention to provide an apparatus and methodfor generation of electricity using a comminuted flow medium, forexample, flowable solids such as stone, ceramic, metal, resins and thelike.

According to one aspect of the invention, a facility for generatingelectricity is provided, that includes a water source; a plurality ofpenstocks adapted for selective flow communication with the water sourcefor delivering water from the water source to a turbine electricitygenerator and an electricity distribution system having a firstcomponent adapted to deliver electricity generated by the turbineelectricity generator to an electric grid and a second component adaptedto use electricity to power an air compressor. A compressed air storagereservoir is provided for storing air compressed by the air compressor,and includes an outlet for selectively delivering the compressed air tothe plurality of penstocks according to a predetermined sequence forproviding energy to the water contained in the selected penstock topropel the water from the penstock to the turbine.

According to one another aspect of the invention, at least a portion ofthe facility components are contained within a structure constructed atleast in part of coal combustion residue.

According to one another aspect of the invention, the water source isselected from the group consisting of a river, channel or canal and awater intake is positioned between the water source and the plurality ofpenstocks. Each of the plurality of penstocks includes a water inflowvalve adapted to control the flow of water from the water source to thepenstock. A water outflow valve is adapted to control the flow of waterfrom the penstock to the turbine electricity generator. A compressed airinflow valve is adapted to control the flow of compressed air from thecompressed air storage reservoir to the penstock. The penstocks convergeto form a single outflow to the turbine electricity generator. Anelectronic control is provided for controlling the operation of thewater inflow valves, the water outflow valves and the compressed airinflow valves.

According to one another aspect of the invention, the compressed air isin flow communication with the water in the selected penstock.

According to one another aspect of the invention, each of the penstocksincludes a piston positioned in the penstock downstream from thecompressed air inflow valve and movable downstream within the penstockby compressed air discharged from the compressed air inflow valve on anupstream side of the piston.

According to one another aspect of the invention, the water intakes arelaterally offset from the respective penstocks and connect to arespective penstock for water flow into the penstocks at a positiondownstream of the compressed air inflow valves and upstream of the wateroutflow valves. A piston is positioned in each of the penstocks upstreamof the respective water outflow valve and downstream of the respectivecompressed air inflow valve and is movable downstream within thepenstocks by compressed air discharged from the compressed air inflowvalve on the upstream side of the piston.

According to one another aspect of the invention, a facility forgenerating electricity is provided that includes a water source and aplurality of penstocks adapted for selective flow communication with thewater source for delivering water from the water source to a turbineelectricity generator. An electricity distribution system is providedhaving a first component adapted to deliver electricity generated by theturbine electricity generator to an electric grid and an alternativesecond component adapted to use the electricity to power an aircompressor. A compressed air storage reservoir is provided for storingair compressed by the air compressor, and includes an outlet forselectively delivering the compressed air to the plurality of penstocksaccording to a predetermined sequence for providing energy to the watercontained in the selected penstock to propel the water from the penstockto the turbine. A structure constructed at least in part of coalcombustion residue is provided and within which at least some of theoperating components of the facility are positioned. A water intake ispositioned between the water source and the plurality of penstocks. Eachof the plurality of penstocks includes a water inflow valve adapted tocontrol the flow of water from the water source to the penstock. A wateroutflow valve is adapted to control the flow of water from the penstockto the turbine electricity generator and a compressed air inflow valveis adapted to control the flow of compressed air from the compressed airstorage reservoir to the penstock.

According to one another aspect of the invention, the penstocks convergeto form a single outflow to the turbine electricity generator; and anelectronic control is provided for controlling the operation of thewater inflow valves, the water outflow valves and the compressed airinflow valves.

According to one another aspect of the invention, the compressed air isin flow communication with the water in the selected penstock, each ofthe penstocks includes a piston positioned in the penstock downstreamfrom the compressed air inflow valve and is movable downstream withinthe penstock by compressed air discharged from the compressed air inflowvalve on an upstream side of the piston.

According to one another aspect of the invention, the water intakes arelaterally offset from the respective penstocks and connect to arespective penstock for water flow into the penstocks at a positiondownstream of the compressed air inflow valves and upstream of the wateroutflow valves. A piston is positioned in each of the penstocks upstreamof the respective water outflow valve and downstream of the respectivecompressed air inflow valve and is movable downstream within thepenstocks by compressed air discharged from the compressed air inflowvalve on the upstream side of the piston.

According to one another aspect of the invention, method of generatingelectricity is provided and includes the steps of providing a watersource, a plurality of penstocks adapted for selective flowcommunication with the water source for delivering water from the watersource to a turbine electricity generator, an electricity distributionsystem having a first component adapted to deliver electricity generatedby the turbine electricity generator to an electric grid and analternative second component adapted to use the electricity to power anair compressor; and a compressed air storage reservoir for storing aircompressed by the air compressor, and an outlet for delivering thecompressed air to the plurality of penstocks for providing energy to thewater contained in the selected penstock to propel the water from thepenstock to the turbine. Water is diverted from the water source intothe plurality of penstocks and the water is delivered downstream to aturbine electricity generator where electricity is generated. Apredetermined portion of the electricity is delivered to an aircompressor for compressing air for storage in a compressed air storagereservoir. The compressed air is delivered to the penstocks forpropelling the water down the penstock to the turbine electricitygenerator.

According to one another aspect of the invention, the step of deliveringthe compressed air to the penstocks is according to a predeterminedrepeating sequence.

According to one another aspect of the invention, the method includesthe step of containing at least a portion of the facility componentswithin a structure constructed at least in part of coal combustionresidue.

According to one another aspect of the invention, the method includesthe step of providing a piston positioned in each penstock downstreamfrom the respective compressed air inflow valve and movable downstreamwithin the penstock by compressed air discharged from the compressed airinflow valve on an upstream side of the piston.

According to one another aspect of the invention, the method includesthe step of laterally offsetting the water intakes from the respectivepenstocks and connecting the water intakes to a respective penstock forwater flow into the penstocks at a position downstream of the compressedair inflow valves and upstream of the water outflow valves.

According to one another aspect of the invention, the method includesthe step of positioning a piston in each of the penstocks upstream ofthe respective water outflow valve and downstream of the respectivecompressed air inflow valve and moving the piston downstream within thepenstocks by compressed air discharged from the compressed air inflowvalve on the upstream side of the piston.

According to one another aspect of the invention, the method includesthe steps of during time periods of relatively high electricity demand,delivering the electricity to an electricity grid and during timeperiods of relatively low electricity demand delivering the electricityto the air compressor.

According to one another aspect of the invention, the method includesthe step of splitting the delivery of electricity from the turbineelectricity generator to an electricity grid and the air compressoraccording to a formula wherein the grid has electricity priority withany excess electricity being delivered to the air compressor.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The present invention is best understood when the following detaileddescription of the invention is read with reference to the accompanyingdrawings, in which:

FIGS. 1-4 are schematic sequential plan views of an apparatus and methodfor generation of electricity using pressurized water and air asrespective flow media; and

FIGS. 5-9 are alternative schematic sequential plan views of anapparatus and method for generation of electricity using pressurizedwater and air as respective flow media.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, a facility 10 for generating electricityaccording to one embodiment is shown in FIGS. 1-4. The facility 10 issited in, for example, a horseshoe bend in a river, a manmade channel orcanal “R”. As shown in the drawings the river R has a gravity-inducedflow indicated by arrows in the streambed. As water flows past theupstream side of the facility 10, water is diverted by an intake 12 intothree penstocks 20, 30 and 40 that deliver the water under pressure to apower house 50 in which is housed a turbine generator 52. The waterexits the power house 50 through an outlet 54 and flows back into theriver R where it joins the water in the river R and flows downstream.Electricity generated in the power house 50 is delivered during peakloads to a power grid 60 for use by customers or during off peak loadtimes to an electrically-powered air compressor 70 that takesenvironmental air, pressurizes it and stores it in a compressed airstorage reservoir 72. An outlet 74 from the reservoir 72 delivers air tothe penstocks 20, 30 and 40 as described below. As needed, power can bescavenged from the grid to generate further compressed air depending onthe level of power usage and the availability of excess power from thegrid.

Preferably, the facility 10, or parts thereof such as the air storagereservoir 72 are encased in, for example, a structure of earth or amixture of coal combustion residue (“CCR”) and other materials 76 toefficiently protect the facility 10 from environmental effects. The useof CCR is a beneficial use that provides a means of efficientlyutilizing an otherwise unusable waste material of which there presentlyexists many millions of tons.

As shown in FIGS. 1-4, the flow of water and compressed air to and fromthe penstocks 20, 30 and 40 is controlled by valves. Water inflow valves80, 82 and 84 are controlled to selectively allow water to flow into thepenstocks 20, 30 and 40, respectively, from the intake 12. Compressedair inflow valves 90, 92 and 94 are controlled to selectively allowcompressed air to flow from the air storage reservoir 72 into thepenstocks 20, 30 and 40. Water outflow valves 100, 102 and 104 arecontrolled to selectively allow water to flow out of the penstocks 20,30 and 40, respectively, to the turbine 52. The sequencing and operationof the facility is controlled by suitable software that is programmed tomonitor operation of the facility 10 and open and close valves accordingthe description of this application.

FIG. 1 illustrates a closed state where the facility 10 is not operatingand the water in the river R bypasses the facility 10 according to itsusual flow.

In FIG. 2, water has flowed into penstock 20 through open water inflowvalve 80, and the water inflow valve 80 has then closed. The penstock20, full of water, is charged with compressed air that flows into theupstream end of the penstock through the open compressed air inflowvalve 90. The compressed air substantially increases the pressure in thepenstock 20. The water outflow valve 100 opens and the pressurized waterdischarges into the power house 50, past the turbine 52 and back intothe river R through the outlet 54. Penstocks 20 and 30 are filling orfull of water while the water in penstock 20 is discharging.

Referring now to FIG. 3, penstock 20 has emptied and has been refilledby closing the water outflow valve 100 and opening water inflow valve80. The compressed air inflow valve 100 is also closed. As water isdischarging from penstock 20, penstock 30 is fully charged with water.Water intake valve 82 is closed and the compressed air inflow valve 92is closed. Water outflow valve 102 is sequenced to open and allow waterin the penstock 30 to discharge into the power house 50 and turbine 52as the last of the water in penstock 20 is discharged through theturbine 52. The process for the penstock 30 sequences as did the processfor penstock 20.

Referring to FIG. 4, the water intake valve 80 opens to allow water toflow into penstock 20, while the water outflow valve 100 and thecompressed air inflow valve 90 close.

As water is discharging from penstock 30, penstock 40 is fully chargedwith water. Water intake valve 84 is closed and the compressed airinflow valve 94 is closed. Water outflow valve 104 is sequenced to openand allow water in the penstock 40 to discharge into the power house 50and turbine 52 as the last of the water in penstock 30 is dischargedthrough the turbine 52. The process for the penstock 40 sequences as didthe process for penstock 30. During operation of the facility 10, theabove-described sequence repeats itself under the control of theprogrammed software. As penstock 40 empties, water intake valve 84 opensto allow water to flow from the water intake 12 into penstock 40, whilewater outflow valve 104 and the compressed air inflow valve 94 closes.

The penstocks 20, 30 and 40 may be angled within a wide range asrequired by the geography of the river R or other factors. Of particularimportance is the ability of the penstocks 20, 30 and 40 to be at a veryshallow angle, since the flow of water is not dictated by the angle ofwater downflow but by the impetus of the compressed air on the water,whether or not in addition to downflow resulting from the downflow angleof the penstocks 20, 30 and 40. As may be desirable due to variousfactors, the angles of the penstocks 20, 30 and 40 may be different,with the water flow rates adjusted as needed by the pressure and volumeof the air being discharged into the penstocks 20, 30 or 40 at any giventime.

Referring now to FIGS. 5-9, a facility 150 for generating electricityaccording to one embodiment is shown. The facility 150 is sited in, forexample, a horseshoe bend in a river or a manmade channel or canal “R”.As shown in the drawings, the river R has a gravity-induced flowindicated by arrows in the streambed. As water flows past the upstreamside of the facility 150, water is diverted by water intakes 152, 154,156 into three respective penstocks 160, 170 and 180 that deliver thewater under pressure to a power house 190 in which is housed a turbinegenerator 192. The water exits the power house 190 through an outlet 194and flows back into the river R where it joins the water in the river Rand flows downstream. Electricity generated in the power house 190 isdelivered during peak loads to a power grid 200 for use by customers orduring off peak load times to an electrically-powered air compressor 210that takes environmental air, pressurizes it and stores it in acompressed air storage reservoir 212. An outlet 214 from the reservoir212 delivers air to the penstocks 160, 170 and 180 as described below.

Preferably, the facility 150, or parts thereof such as the air storagereservoir 212 is encased in, for example, a structure of earth or amixture of coal combustion residue (“CCR”) and other materials 216 toefficiently protect the facility 150 from environmental effects. The useof CCR is a beneficial use that provides a means of efficientlyutilizing an otherwise unusable waste material of which there presentlyexists many millions of tons.

As also shown in FIGS. 5-9, the flow of water and compressed air to andfrom the penstocks 160, 170 and 180 is controlled by valves. Waterinflow valves 220, 222 and 224 are controlled to selectively allow waterto flow into the penstocks 160, 170 and 180, respectively, from theintakes 152, 154 and 156. Compressed air inflow valves 230, 232 and 234are controlled to selectively allow compressed air to flow from theoutlet 214 of the air storage reservoir 212 into the penstocks 160, 170and 180. Water outflow valves 240, 242 and 224 are controlled toselectively allow water to flow out of the penstocks 160, 170 and 180,respectively, to the turbine 192. The penstocks 160, 170, and 180include pistons 162, 172, and 182, respectively that are positioned formovement in the penstocks 160, 170 and 180 downstream of the air inflowvalves 230, 232 and 234, and upstream of the water outflow valves 240,242 and 224.

The sequencing and operation of the facility is controlled by suitablesoftware that is programmed to monitor operation of the facility 150 andopen and close valves according the description of this application.

FIG. 5 illustrates a closed state where the facility 150 is notoperating and the water in the river R bypasses the facility 150 andassumes its usual flow.

In FIG. 6, water has flowed into penstock 160 through open water inflowvalve 220, and the water inflow valve 220 has closed. The penstock 160,full of water, is charged with compressed air that flows into theupstream end of the penstock 160 through the open compressed air inflowvalve 230. The compressed air substantially increases the pressure inthe penstock 160 upstream of the piston 162. The water outflow valve 240opens and the pressurized water propels the piston 162 downstream in thepenstock 160, causing the water to discharge into the power house 190,past the turbine 192 and back into the river R through the outlet 194.Penstocks 170 and 180 are filling or full of water while the water inpenstock 160 is discharging.

Referring now to FIG. 7, penstock 160 has emptied and has been refilledby closing the water outflow valve 240 and opening water inflow valve220. The compressed air inflow valve 230 is also closed. As water isdischarging from penstock 160, penstock 170 is fully charged with water.Water intake valve 172 is closed and the compressed air inflow valve 232is closed.

Water outflow valve 242 is sequenced to open and allow water in thepenstock 170 to discharge into the power house 190 and turbine 192 asthe last of the water in penstock 160 is discharged through the turbine192. The process for the penstock 170 sequences as did the process forpenstock 160.

Referring to FIG. 8, the water inflow valve 220 opens to allow water toflow into penstock 160, while the water outflow valve 240 and thecompressed air inflow valve 230 close. The water flowing into thepenstock 160 through the water inflow valve 220 pushes the pistonupstream in the penstock 160 and into its ready position shown in FIG.8.

As water is discharging from penstock 170, penstock 180 is fully chargedwith water. Water intake valve 224 is closed and the compressed airinflow valve 234 is closed. Water outflow valve 244 is sequenced to openand allow water in the penstock 180 to discharge into the power house190 and turbine 192 as the last of the water in penstock 170 isdischarged through the turbine 192. The process for the penstock 180sequences as did the process for penstock 170. During operation of thefacility 150, the above-described sequence repeats itself under thecontrol of the programmed software. As penstock 180 empties, waterintake valve 224 opens to allow water to flow from the water intake 224into penstock 180, while water outflow valve 244 and the compressed airinflow valve 234 closes.

The penstocks 160, 170 and 180 may be angled within a wide range asrequired by the geography of the river R or other factors. Of particularimportance is the ability of the penstocks 160, 170 and 180 to be at avery shallow angle, since the flow of water is not dictated by the angleof water downflow but by the impetus of the compressed air-drivenpistons 162, 172, 182 on the water, whether or not in addition todownflow resulting from the downflow angle of the penstocks 160, 170 and180. As may be desirable due to various factors, the angles of thepenstocks 160, 70 and 180 may be different, with the water flow ratesadjusted as needed by the pressure and volume of the air beingdischarged into the penstocks 160, 70 or 80 at any given time.

As shown in FIG. 9, an air vent 250 controlled by an air valve 252allows air to vent to the environment as the angle of the water intake152 permits water to flow down to the level of the penstock 160 throughthe open water inflow valve 220, where it backfills into the penstock160. As noted above, the ability of the compressed air to provideimpetus to the water permits an arrangement as shown in FIG. 9. As alsonoted, other arrangements are possible.

As also shown in FIG. 9, CCR may be used as a construction material toencase all or substantially all of the operating components of thefacility 10, not just the compressed air storage reservoir 212.

While water has been described as the vehicle for rotating the turbines52 and 192, other non-compressible flow media may be used, includingvarious comminuted flowable solids, such as stone, ceramic, metal,resins and the like. In such instances the comminuted materials arecontained in a closed system by which they fall under the influence ofgravity through a turbine and are carried by conveyer back to anupstream position for introduction into one or more penstocks.

An apparatus and method for generation of electricity using pressurizedwater and air as respective flow media according to the invention havebeen described with reference to specific embodiments and examples.Various details of the invention may be changed without departing fromthe scope of the invention. Furthermore, the foregoing description ofthe preferred embodiments of the invention and best mode for practicingthe invention are provided for the purpose of illustration only and notfor the purpose of limitation, the invention being defined by theclaims.

We claim:
 1. A facility for generating electricity, comprising: (a) awater source; (b) a plurality of penstocks adapted for selective flowcommunication with the water source for delivering water from the watersource to a turbine electricity generator; (c) an electricitydistribution system having a first component adapted to deliverelectricity generated by the turbine electricity generator to anelectric grid and a second component adapted to use electricity to poweran air compressor; and (d) a compressed air storage reservoir forstoring air compressed by the air compressor, and including an outletfor selectively delivering the compressed air to the plurality ofpenstocks according to a predetermined sequence for providing energy tothe water contained in the selected penstock to propel the water fromthe penstock to the turbine.
 2. A facility for generating electricityaccording to claim 1, wherein at least a portion of the facilitycomponents are contained within a structure constructed at least in partof coal combustion residue.
 3. A facility for generating electricityaccording to claim 1, wherein: (a) the water source is selected from thegroup consisting of a river, channel or canal; (b) a water intake ispositioned between the water source and the plurality of penstocks; (c)each of the plurality of penstocks includes a water inflow valve adaptedto control the flow of water from the water source to the penstock; (d)a water outflow valve is adapted to control the flow of water from thepenstock to the turbine electricity generator; (e) a compressed airinflow valve is adapted to control the flow of compressed air from thecompressed air storage reservoir to the penstock; (f) the penstocksconverge to form a single outflow to the turbine electricity generator;and (g) an electronic control is provided for controlling the operationof the water inflow valves, the water outflow valves and the compressedair inflow valves.
 4. A facility for generating electricity according toclaim 3, wherein the compressed air is in flow communication with thewater in the selected penstock.
 5. A facility for generating electricityaccording to claim 3, wherein each of the penstocks includes a pistonpositioned in the penstock downstream from the compressed air inflowvalve and movable downstream within the penstock by compressed airdischarged from the compressed air inflow valve on an upstream side ofthe piston.
 6. A facility for generating electricity according to claim3, wherein the water intakes are laterally offset from the respectivepenstocks and connect to a respective penstock for water flow into thepenstocks at a position downstream of the compressed air inflow valvesand upstream of the water outflow valves, and further wherein a pistonis positioned in each of the penstocks upstream of the respective wateroutflow valve and downstream of the respective compressed air inflowvalve and movable downstream within the penstocks by compressed airdischarged from the compressed air inflow valve on the upstream side ofthe piston.
 7. A facility for generating electricity, comprising: (a) awater source; (b) a plurality of penstocks adapted for selective flowcommunication with the water source for delivering water from the watersource to a turbine electricity generator; (c) an electricitydistribution system having a first component adapted to deliverelectricity generated by the turbine electricity generator to anelectric grid and an alternative second component adapted to use theelectricity to power an air compressor; (d) a compressed air storagereservoir for storing air compressed by the air compressor, andincluding an outlet for selectively delivering the compressed air to theplurality of penstocks according to a predetermined sequence forproviding energy to the water contained in the selected penstock topropel the water from the penstock to the turbine; (e) a structureconstructed at least in part of coal combustion residue and within whichat least some of the operating components of the facility arepositioned; (f) a water intake positioned between the water source andthe plurality of penstocks; and (g) each of the plurality of penstocksincluding a water inflow valve adapted to control the flow of water fromthe water source to the penstock; a water outflow valve adapted tocontrol the flow of water from the penstock to the turbine electricitygenerator; and a compressed air inflow valve adapted to control the flowof compressed air from the compressed air storage reservoir to thepenstock.
 8. A facility for generating electricity according to claim 7,wherein: (h) the penstocks converge to form a single outflow to theturbine electricity generator; and (i) an electronic control is providedfor controlling the operation of the water inflow valves, the wateroutflow valves and the compressed air inflow valves.
 9. A facility forgenerating electricity according to claim 8, wherein the compressed airis in flow communication with the water in the selected penstock andeach of the penstocks includes a piston positioned in the penstockdownstream from the compressed air inflow valve and movable downstreamwithin the penstock by compressed air discharged from the compressed airinflow valve on an upstream side of the piston.
 10. A facility forgenerating electricity according to claim 9, wherein the water intakesare laterally offset from the respective penstocks and connect to arespective penstock for water flow into the penstocks at a positiondownstream of the compressed air inflow valves and upstream of the wateroutflow valves, and further wherein a piston is positioned in each ofthe penstocks upstream of the respective water outflow valve anddownstream of the respective compressed air inflow valve and movabledownstream within the penstocks by compressed air discharged from thecompressed air inflow valve on the upstream side of the piston.
 11. Amethod of generating electricity, comprising the steps of: (a) providinga water source, a plurality of penstocks adapted for selective flowcommunication with the water source for delivering water from the watersource to a turbine electricity generator, an electricity distributionsystem having a first component adapted to deliver electricity generatedby the turbine electricity generator to an electric grid and analternative second component adapted to use the electricity to power anair compressor; and a compressed air storage reservoir for storing aircompressed by the air compressor, and including an outlet for deliveringthe compressed air to the plurality of penstocks for providing energy tothe water contained in the selected penstock to propel the water fromthe penstock to the turbine; (b) diverting water from the water sourceinto the plurality of penstocks; (c) delivering the water downstream toa turbine electricity generator where electricity is generated; (d)delivering a predetermined portion of the electricity to an aircompressor; (e) compressing air for storage in the compressed airstorage reservoir; and (f) delivering the compressed air to thepenstocks for propelling the water down the penstock to the turbineelectricity generator.
 12. A method of generating electricity accordingto claim 11, and including the step of delivering the compressed air tothe penstocks according to a predetermined repeating sequence.
 13. Amethod of generating electricity according to claim 11, and includingthe step of containing at least a portion of the facility componentswithin a structure constructed at least in part of coal combustionresidue.
 14. A method of generating electricity according to claim 11,and including the step of providing a piston positioned in each penstockdownstream from the respective compressed air inflow valve and movabledownstream within the penstock by compressed air discharged from thecompressed air inflow valve on an upstream side of the piston.
 15. Amethod of generating electricity according to claim 11, and includingthe step of laterally offsetting the water intakes from the respectivepenstocks and connecting the water intakes to a respective penstock forwater flow into the penstocks at a position downstream of the compressedair inflow valves and upstream of the water outflow valves.
 16. A methodof generating electricity according to claim 15, and including the stepof positioning a piston in each of the penstocks upstream of therespective water outflow valve and downstream of the respectivecompressed air inflow valve and movable downstream within the penstocksby compressed air discharged from the compressed air inflow valve on theupstream side of the piston.
 17. A method of generating electricityaccording to claim 11, including the steps of during time periods ofrelatively high electricity demand, delivering the electricity to anelectricity grid and during time periods of relatively low electricitydemand delivering the electricity to the air compressor.
 18. A method ofgenerating electricity according to claim 11, including the step ofsplitting the delivery of electricity from the turbine electricitygenerator to an electricity grid and the air compressor according to aformula wherein the grid has electricity priority with any excesselectricity being delivered to the air compressor.